Wireless communication apparatus for changing directional pattern of variable directivity antenna according to variations in radio wave propagation enviroment

Abstract

When a variable directivity antenna apparatus is controlled to form an initial composite directional pattern, RSSI is measured, and a weak electric field group or an intense electric field group is selected based on the measured RSSI. When the variable directivity antenna apparatus is controlled to form the composite directional patterns included in the selected composite directional pattern group, PER for each of the composite directional patterns is measured, and one composite directional pattern is selected from among the composite directional patterns included in the selected composite directional pattern group based on the measured PER, so that the variable directivity antenna apparatus is controlled to form the selected composite directional pattern.

1 - 9 . (canceled) 
     
     
         10 . A wireless communication apparatus comprising:
 a variable directivity antenna apparatus comprising at least one variable directivity antenna element, and forming a plurality of composite directional patterns each of which is a superposition of respective directional patterns of the at least one variable directivity antenna element;   a storage device for previously storing therein composite directional pattern classification information on classification of the plurality of composite directional patterns into a plurality of composite directional pattern groups set by using a first parameter representing a quality level of a wireless signal received by the variable directivity antenna apparatus; and   a controller for selecting one composite directional pattern from among the plurality of composite directional patterns based on the first parameter and a second parameter, and for controlling the composite directional pattern of the variable directivity antenna apparatus so that the variable directivity antenna apparatus forms a selected composite directional pattern, the second parameter representing the quality level of the wireless signal and being different from the first parameter.   
     
     
         11 . The wireless communication apparatus as claimed in  claim 10 ,
 wherein (a) when the controller controls the variable directivity antenna apparatus to form one predetermined composite directional pattern among the plurality of composite directional patterns, the controller measures the first parameter, and selects one composite directional pattern group from among the plurality of composite directional pattern groups with reference to the composite directional pattern classification information based on a measured first parameter,   wherein (b) when the controller controls the variable directivity antenna apparatus to form composite directional patterns included in a selected composite directional pattern group, the controller measures second parameters for the composite directional patterns included in the selected composite directional pattern group, respectively, and selects one composite directional pattern from among the composite directional patterns included in the selected composite directional pattern group based on respective measured second parameters; and   wherein (c) the controller controls the variable directivity antenna apparatus to form a selected composite directional pattern.   
     
     
         12 . The wireless communication apparatus as claimed in  claim 11 ,
 wherein the controller measures a third parameter representing the quality level of the wireless signal when the controller controls the variable directivity antenna apparatus to form the selected composite directional pattern, judges whether or not a measured third parameter is equal to or smaller than a predetermined first threshold value, and controls the variable directivity antenna apparatus to form a further composite directional pattern other than the selected composite directional pattern upon detecting that the measured third parameter is equal to or smaller than the first threshold value.   
     
     
         13 . The wireless communication apparatus as claimed in  claim 12 ,
 wherein the controller controls the variable directivity antenna apparatus to form the further composite directional pattern other than the selected composite directional pattern upon detecting that the measured third parameter is equal to or smaller than the first threshold value a predetermined threshold times successively.   
     
     
         14 . The wireless communication apparatus as claimed in  claim 13 ,
 wherein the controller measures the first parameter when the controller controls the variable directivity antenna apparatus to form the selected composite directional pattern,   calculates a reference first parameter based on the first parameter measured immediately after starting the control,   calculates a last first parameter based on the first parameter measured immediately before the detection,   selects the further composite directional pattern from among all of the plurality of composite directional patterns when a magnitude of a difference between a calculated reference first parameter and the last first parameter is equal to or larger than a predetermined second threshold value, and   selects the further composite directional pattern from among the composite directional patterns other than the selected composite directional patter and included in the selected composite directional pattern group when the magnitude of the difference between the calculated reference first parameter and the last first parameter is smaller than the predetermined second threshold value.   
     
     
         15 . The wireless communication apparatus as claimed in  claim 11 ,
 wherein the third parameter is the same as the second parameter.   
     
     
         16 . The wireless communication apparatus as claimed in  claim 11 ,
 wherein the predetermined one composite directional pattern is substantially omnidirectional.   
     
     
         17 . The wireless communication apparatus as claimed in  claim 10 ,
 wherein the first parameter represents a received signal level of the wireless signal.   
     
     
         18 . The wireless communication apparatus as claimed in  claim 10 ,
 wherein, for each of the composite directional patterns, the composite directional pattern classification information includes data on the directional patterns of the respective variable directivity antenna elements and data on the directional pattern group which is selected from among the plurality of composite directional pattern groups and in which the composite directional pattern is included.